#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define nl cout<<"\n"
#define ca(v) for(auto i:v) cout<<i<<" ";
ll delivery(int N, int K, int L, int* a){
vector<ll> ar;
for(int i=0; i<N; i++) ar.push_back((ll)a[i]);
sort(ar.begin(), ar.end());
vector<vector<ll>> cost(N, vector<ll>(2, 0));
for(int i=0; i<N; i++){
if(i<K) {
cost[i][0] = ar[i] + min(ar[i], L - ar[i]);
cost[N-1-i][1] = (L - ar[N-1-i]) + min(ar[N-1-i], L - ar[N-1-i]);
}
else {
cost[i][0] = ar[i] + min(ar[i], L - ar[i]) + cost[i-K][0];
cost[N-1-i][1] = (L - ar[N-1-i]) + min(ar[N-1-i], L - ar[N-1-i]) + cost[N-1-i+K][1];
}
}
ll ans = cost[0][1];
ans = min(ans, cost[N-1][0]);
for(int i=0; i<N-1; i++){
ans = min(ans, cost[i][0] + cost[i+1][1]); //- max(min(ar[i], L - ar[i]), min(ar[i+1], L - ar[i+1])));
}
return ans;
}
// int main()
// {
// ios_base::sync_with_stdio(0); cin.tie(0);
// if (fopen("input.in", "r")) freopen("input.in", "r", stdin);
// int N, K, L;
// cin>>N>>K>>L;
// vector<int> ar(N);
// for(int i=0; i<N; i++) cin>>ar[i];
// cout<<delivery(N, K, L, ar);
// }
